Had a sub put down a K-15 equal all across the floor, they left small ridges in the floor where I guess there screed pulled across the floor. Our installer says it all has to be either feather skim coated or they need to take a large grinder to the floor and lightly knock the edges down. Ever happen to you? How to fix?

Aslo are small holes in the underlayment, they look like bugs bore through or micro bubbles or something normal?